Finishing manner null of AL alloy die-cast and AL alloy die-cast it possesses abrasion resistance and

摘要

PURPOSE:To improve the wear resistance and lubricity of an Al or Al alloy material such as a foundry Al alloy by anodically oxidizing the surface of the material contg. an eutectic phase and by substituting a metal having high lubricity or wear resistance for the eutectic phase in the resulting oxide coating film to form a composite coating film. CONSTITUTION:The surface of an Al or Al alloy material 1 contg. an eutectic phase 2 such as a foundry Al alloy including a die casting Al alloy is anodically oxidized and a metal 5 having high lubricity or wear resistance is substd. for the eutectic phase 2 in the resulting oxide coating film 4 to form a composite coating film. This composite coating film may be formed by selectively dissolving and removing the eutectic phase 2 in the surface of the material 1, anodically oxidizing the surface of the material 1 and filling the metal 5 into holes pierced in the resulting oxide coating film by the absence of the eutectic phase 2. The wear resistance and lubricity of the Al or Al alloy material can be improved.